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Mixed-Layer Clay Geothermometry in the Wairakei Geothermal Field, New Zealand

Published online by Cambridge University Press:  02 April 2024

Colin Charles Harvey  and
Patrick R. L. Browne
Colin Charles Harvey*
Affiliation:
Geothermal Institute and Department of Geology, University of Auckland, Private Bag Auckland, New Zealand
Patrick R. L. Browne
Affiliation:
Geothermal Institute and Department of Geology, University of Auckland, Private Bag Auckland, New Zealand
*
1Present address: Dept. of Geology, Indiana University, Bloomington, Indiana.
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Abstract

Mixed-layer clays of variable composition and structure occur in core samples from two drillholes (WK207 and WK210) drilled into the Te Mihi sector of the Wairakei geothermal field. These were identified by X-ray diffraction analysis of glycolated and oriented sample fractions at less than 2 μm and less than 0.2 μm.

Low permeability lacustrine sediments encountered by drillhole WK207 contain a well-developed sequence of mixed-layer clays. The shallowest downhole appearance of mixed-layered illite/smectite (I0.6/Sm) occurs at 146 m depth where temperature is only 100°C. Discrete illite is present only below 297 m (200°C) in the finer size fraction (less than 0.2 ¼m). Chlorite first appears downhole, in association with illite-smectite, at 177 m depth (110°C).

Drillhole WK210 encountered predominantly ignimbrites and rhyolites, and fluid flow here is mainly in channels. Within these rocks, a sequence of interlayered clays is poorly developed. Discrete illite and chlorite are present in core from only 244 m (180°), but the measured temperatures where interlayer clays occur ranges from 140 to 209°C.

Differences in the identity of clay minerals present in the Wairakei reservoir, where conditions are otherwise the same, demonstrate the strong control that the type of fluid flow has on their formation. In poorly-permeable sediments, where diffuse fluid flow prevails, a clearly-defined sequence of mixed-layer clays occurs. These are absent where channel flow dominates, the discrete chlorite and illite deposit directly from solution.

Keywords

Geothermal systemHydrothermal alterationMixed-layer claysReservoir permeability
Type
Research Article
Information
Clays and Clay Minerals , Volume 39 , Issue 6 , December 1991 , pp. 614 - 621
Copyright
Copyright © 1991, The Clay Minerals Society

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References

Ahn, H. A. and Peacor, D. R., 1985 Transmission electron microscopic studies of authigenic chlorite in Gulf Coast argillaceous sediments Clays & Clay Minerals 33 228 – 236.CrossRefGoogle Scholar
Bird, D. K., Schiffman, P., Elders, W. A., Williams, A. E. and McDowell, S. D., 1984 Calc-silicate mineralisation in active geothermal systems Econ. Geol. 79 671 – 695.CrossRefGoogle Scholar
Brindley, G. W. and Brown, G., 1980 Crystal Structures of Clay Minerals and their X-ray Identification London Mineralogical Society.CrossRefGoogle Scholar
Browne, P. R. L., 1970 Hydrothermal alteration as an aid in investigating geothermal fields Geothermics 2 564 – 570.CrossRefGoogle Scholar
Browne, P. R. L., 1978 Hydrothermal alteration in active geothermal fields Ann. Rev. Earth Planet. Sci. 6 229 – 250.CrossRefGoogle Scholar
Burst, J. F. Jr., 1958 Glauconite pellets: Their mineral nature and applications for stratigraphie interpretation Amer. Assoc. Petrol. Geol. Bull. 42 310 – 327.Google Scholar
Burst, J. F. Jr. and Swineford, A., 1959 Post diagenetic clay mineral environmental relationships in the Gulf Coast Eocene Clays and Clay Minerals, Proc. 6th Natl. Conf., Berkeley, California, 1957. New York Pergamon Press 327 – 341.Google Scholar
Cathelineau, M., 1988 Cation site occupancy in chlorites and illites as a function of temperature Clay Mineral. 23 471 – 485.CrossRefGoogle Scholar
Cathelineau, M. and Izquierdo, G., 1988 Temperaturecomposition relationships of authigenic micaceous minerals in the Los Azufres geothermal system Contrib. Mineral. Petrol. 100 418 – 428.CrossRefGoogle Scholar
Chang, H. K., McKenzie, F. T. and Schoonmaker, J., 1986 Comparison between diagenesis of dioctahedral and trioctahedral smectite, Brazilian offshore basins Clays & Clay Minerals 34 407 – 423.CrossRefGoogle Scholar
Cole, J.W., 1990 Structural control and origin of volcanism in the Taupo Volcanic Zone, New Zealand Bull. Volcanol. 52 445 – 459.CrossRefGoogle Scholar
Grindley, G. W. (1965) The geology, structure, and exploitation of the Wairakei geothermal field, Taupo, New Zealand: N.Z. Geol. Surv. Bull. 75, 131 pp.Google Scholar
Hoffman, J. and Hower, J., 1979 Clay mineral assemblages as low grade metamorphic geothermometers: Application to the thrust-faulted disturbed belt of Montana, U.S.A. Aspects of Diagenesis 26 55 – 79.CrossRefGoogle Scholar
Iijima, A., Utada, M. and Gould, R. F., 1971 Present-day diagenesis of the Neogene géosynclinal deposits in the Niigata Oilfield, Japan Molecular Sieve Zeolites—I Washington, D.C. Advances in Chemistry Series 101, American Chemical Society 342 – 349.Google Scholar
Jackson, M. L., 1969 Soil Chemical Analysis—Advanced Course 2nd Wisconsin published by the author, Madison.Google Scholar
Jennings, S. and Thompson, G. R., 1986 Diagenesis of PlioPleistocene sediments of the Colorado River Delta, southern California J. Sediment. Petrol. 56 89 – 98.Google Scholar
Kristmannsdóttir, H., 1976 Types of clay minerals in hydrothermally altered basaltic rocks, Reykjanes, Iceland Jokull 26 30 – 39.Google Scholar
Kristmannsdóttir, H. and Tómasson, J., 1976 Hydrothermal alteration in Icelandic geothermal fields Soc. Sci. Islandica 167 – 176.Google Scholar
Lee, J. H., Peacor, D. R., Lewis, D. D. and Wintsch, R. P., 1984 Chlorite-illite/muscovite interlayered and interstratified crystals: A TEM-AEM study Contrib. Mineral. Petrol. 88 372 – 385.CrossRefGoogle Scholar
Nadeau, P. H. and Reynolds, C. R., 1981 Burial and contact metamorphism in the Mancos Shale Clays & Clay Minerals 29 249 – 259.CrossRefGoogle Scholar
Perry, E. and Hower, J., 1970 Burial diagenesis in Gulf Coast pelitic sediments Clays & Clay Minerals 18 165 – 177.CrossRefGoogle Scholar
Reynolds, R. C., Brindley, G. W. and Brown, G., 1980 Interstratified clay minerals Crystal Structures of Clay Minerals and their X-ray Identification London Mineralogical Society 249 – 303.CrossRefGoogle Scholar
Steiner, A., 1953 Hydrothermal rock alteration at Wairakei, New Zealand Econ. Geol. 48 1 – 13.CrossRefGoogle Scholar
Steiner, A., 1968 Clay minerals in hydrothermally altered rocks at Wairakei, New Zealand Clays & Clay Minerals 16 193 – 213.CrossRefGoogle Scholar
Steiner, A. (1977) The Wairakei Geothermal Area, North Island, New Zealand: N.Z. Geol. Surv. Bull. 90, 136 pp.Google Scholar
Tomasson, J. and Kristmannsdôttir, H., 1972 High temperature alteration minerals and geothermal brine, Reykjanes, Iceland Contrib. Mineral. Petrol. 36 123 – 134.CrossRefGoogle Scholar
Weaver, C. E., 1956 The distribution and identification of mixed-layer clays in sedimentary rocks Amer. Mineral. 41 202 – 221.Google Scholar
Wood, C. P., 1990 Unpublished internal report to Electricorp Ltd., on the stratigraphy in the Te Mihi sector of the Wairakei Geothermal Field, New Zealand .Google Scholar
Yau, Y.-C. Peacor, D. C., Beane, R. E. and Essene, E. J., 1988 Microstructures, formation mechanisms, and depthzoning of phyllosilicates in geothermally altered shales, Salton Sea, California Clays & Clay Minerals 36 1 – 10.Google Scholar
Youngman, K. J., 1989 Hydrothermal alteration and thermal evolution of the Wairakei geothermal field New Zealand Ph.D. thesis, University of Auckland.Google Scholar
Zhang, L., 1989 Hydrothermal alteration and fluid-rock interaction in drillholes WK215 and WK207, Wairakei Geothermal Field, New Zealand New Zealand M.Sc. thesis, University of Auckland.Google Scholar